Grinding machine



Feb. 2 4, 1948. P. H. WALTHER GRINDING MACHINE Filed June 28, 1944 INVENTOR PAUL H WALTHER BY l TTOTNEY Patented Feb. 24, 1948 GRINDING MACHINE Paul H. Walther, St. Louis, Mo., assis-nor to Carter Carburetor Corporation, St. Louis, Mo., a

corporation of Delaware Application June 2s, 1944, serial No. 542,473

5 claims. (ci. 51-232) This invention relates particularly to improvements in machines for grinding tools and more specifically to a work holder for use in grinding operations wherein the parts are so constructed and arranged that both back-oi and center grinding operations are practical by relatively slight adjustments of the parts forming the assembly. y

One of the objects of this invention is to form the parts oi the device so that transition is not only quiclrly performed but this operation can be accomplished with necessary accuracy and efdciency and without possibility of unintentional movement of the various parts interfering with such operation.

Another object resides in the provision of a construction whereby the adaptability oi the device to any suitable base and with any desired angular adjustment is practical.

Another object is to so mount the assembly that a maximum number of parts, including bearings are completely housed during all operations.

Other objects will inore clearly hereinafter appear by reference to the accompanying drawings forming a part of this specification, and wherein like characters of reference designate corresponding parts in which Fig. l is a quarter section of the device as used for back-od grinding.

Fig. 2 is a similar view of the device used for center grinding, and

Fig. 3 is a side elevation oi the adjusting cam.

While any suitable support may be used, there is illustrated in the present disclosure a base plate i having bolt openings whereby it may be bolted by bolts ii to any machine or standard. This base plate is vertically positioned to form the lower section of a swivel support, completed by intermediate member 3 rotatable on central connecting bolt fl and having the horizontal surface suitably graduated for adjustment and upon which is mounted the top supporting element 6 movable about pivot bolt 'l on the horizontal supporting surface 5. The supporting elements t include the cylindrical housing B in which are arranged the bearings for alignment and rotation of the spindle il. The spindle 9 is mounted within the bearings it and il seated at the front and rear ends of the cylindrical housing 8 and is freely rotatable at all times within these bearings. The front bearing ill is confined between the annular shoulder i2 of the housing and the retaining closure plate I4 xed at the end of the housing by screws or bolts l5.

The rear bearing li is confined between the annular shoulder I6 of the housing and the rear closure plate il of the housing. The outer races i 3 and l 9 of the bearing assemblies are thus xed in the housing 8 and the inner races 2li and 2l are mounted upon and permit free longitudinal sliding movement of the spindle 9. To urge the spindle toward an extended position with respect to the housing there is provided a xed collar 23 on the spindle 9 and a stop collar 24v abutting against the inner race 2l of the inner bearing and between which a coiled spring 2li'` is positioned. This spring normally urges cam 25 on the spindle against roller bearing 2Q carried by the housings, as will more clearly hereinafter appear.

For use in a manual back-oir operation where it is essential that the spindle be reciprocated axially and in a direction transverse to the peripheral surface o the rotating grinder A, the cam 225 xed on the spindle by key 25' cooperates with the bearing roller 2d on the pin 3G mounted between the spaced walls 3i and 32 projecting from the rear face of the end plate il. Roller 29 is positioned so that its axis intersects the axis of the spindle and thus the distribution of the thrust from the cam is properly distributed to eliminate weer of the moving parts. The cam is removable over the left end oi the spindle and, in its working position, is backed by a threaded collar With the parts as illustrated in Fig. 1 it will be apparent that oscillation or rotation of the spindle by manual engagement with the knurled pulley 33 will cause the cam 2S to move the spindle axially of the housing and thus move the work piece B across the peripheral face of the rotary grinding wheel A. As the rise of the cam diminishes the spring will cause the outward movement of the spindle il to the limit defined by the setting oi' the collar Qii.

Rearwardly extending from the cylindrical housing t is the housing section 3@ enclosing the roller 29, cam 25 and collar This housing section is essentially cylindrical in form, and of less diameter than the main housing Si to snugly encase the parts mentioned. The outer end of the housing section 35 is flanged radially outwardly at 37 to provide for the passage of screws or bolts Sil which have the dual function oi" fastening the rear end wall il and housing section 35 to the end portion of the main housing 8. The inner end of the housing section 36. is anged radially inwardly at 391:0 snugly enclose the spindle 5 and the lengthof this housing sec- 3 tion is such as to permit maximum movement therein of the adjustable collar 33 so as to permit disengagement of the cam 25 and roller 29 as shown in Fig. 2.

The collar 45 threaded on the spindle 9 at 40', includes the outer knurled body portion 4| through which the set screw 42 extends for locking same in its adjusted position on the spindle 9 and the forwardly extending cylindrical portion 43 which defines a recess in which are located the thrust ball bearings 44 enclosed by raceways 45 and 4I. Left hand raceway 49 seats against the adjacent inner vertical face of the recess while right hand raceway 45 projects slightly outwardly of the end of cylindrical portion 43 for direct contact with the adjacent face 48 of flange 39. on housing section 35. By this arrangement adjustment of the collar 40 rightwardly on the spindle 9 will cause the projecting face of the raceway 45 to abut housing ange 39 and urge the spindle leftwardly relative to the housings, against the tension of spring 24', to cause suitable separation between the cam 25 and the collar`23 and thus render ineffective the cam action on the spindle. With the parts in the relative positions just described it will be apparent that application of power to the pulley 33 by means of belt E will result in the rotation of the spindle 9 independent of any axial movement of this part.

In use of the device as a back-H grinder, and with particular reference to Figure l, it will be apparent to one skilled in the art that the work B, which may for instance be a stepped machine tool, is initially clamped in the expansible chuck C by manipulation of the hand nut 50. The rotation of the hand nut 50 and hollow stem 5i to which the-nut 50 is ilxed, urges the chuck C axially because of the threaded connection 52 between the stem and chuck C. A spline 53 interposed between the chuck C and the inner face` of the thickened wall portion 54 of the spindle 3 prevents rotation of the chuck during this adjustment and by the aid of spring 24' insures rotation of the work during operation of the spindie. When the work piece is chucked and a backoi operation is desirable, the drive belt normally operating in the groove 55 of the combined pulley and hand wheel 33' is disengaged and the hand wheel turned through the required arc manually 5o to cause axial movement of the Work B across the peripheral rotating face of the grinder A. This operation being carried out to the extent desired and through cooperation of roher 29, cam and spring 24', results in an accurate grindment on the spindle.

In center grinding the hand nut 40 is un-f locked by disengaging screw 42 from the spindle 60 the spindle to rotate freely-by power through a 70 suitable belt `E driving the pulley 33'. This assembly and operation is illustrated in Figure 2 of the drawings. A closure ring 55 is provided to complete the assembly, this Vring vbeing of -man am .ma nf- 111mm ner-duel nps-through 75 of said raceways and'tensioned to position said which the clamp screw 51 passes for tightening.

The assembly is compact, well balanced for all possible operations, and capable of a multiplicity of adjustments and replacements permitl ting substantial scope in possible operations obvious to one skilled in the art. The exclusive use of all modiilcations as come within the scope of the appended claims is contemplated.

I claim:

1. In a work holder for grinding machines, a base, a cylindrical housing supported by said base. a spindle axially positioned in said housing, bearings interposed between said spindle and housing whereby said spindle is capable of rotatable and axial movement, a spring in said housing nor.. mally urging said spindle in one direction, a'cam and a cam follower carried by the housing and spindle individually and operable to shift said spindle during rotation against the tension of said 20 spring, means threaded on -said spindle and engaging said housing for shifting the former to render said cam inoperative, and a chuck carried by said spindle.

2. In a device of the character described, a base, main and auxiliary cylindrical housings supported by said base, a rotatable spindle having its intermediate portion enclosed by said housings, spaced bearings interposed between said spindle and the main housing, said bearings including outer raceways fixed in said hy using and inner raceways slidable on said spindle, a spring engaging one of said raceways and tensioned to position said spindle with respect to said housing, a cam carried by said spindle and enclosed in said auxiliary housing, a bearing surface carried by the main housing and engaging said cam to cause axial movement of the spindle against said spring tension, a hand wheel threaded on said spindle for shifting lsaid spindle relative to said housings to cause engagement and disengagement between said cam and said bearing por-f tion, said last-named means being positioned rearward of the auxiliary housing and comprising a hand wheel threaded on said spindle, a drive pulley for said spindle, and a. work engaging chuck.

3. In a device of the character described, a base, a housing supported by said base, a rotatable spindle having a drive wheel and having its intermediate portion enclosed by said housing, a, cam carried by said spindle within said housing, a cam follower mounted on said housing adjacent said cam, spaced bearings interposed between said spindle 'and said housing and sldably receiving said spindle, a spring stressed between said housing and said spindle and normally urging said cam ing operation within the predetermined limits permitted by the riseof cam 25 and its adjustagainst said follower so as to produce axial'movements of said spindle during rotation thereof by y an end thrust roler bearing interposed between said hand wheel and housing.

5. In a device of the character described, a base. main and auxiliary cylindrical housings supported by said base, a rotatable spindle having its intermediate portion enclosed by said housings, spaced bearings interposed between said spindle* and the main housing, said bearings including outer race-v ways iixed in said housing and inner raceways slidable on said spindle,` a. spring engagingone spindle with respect to said housing, a cam carried by said spindle and enclosed in said auxiliary hcusing, a. bearing surface carriedby the main housing and engaging said cam to cause axial movement of the spindle against said spring tension, means for shifting said spindle relative to said housings to cause engagement and disengagement between said cam and said bearing portion, said last-named means being positioned rearward of the auxiliary housing and including a hand wheel threaded on said spindle and a freelyrotatable bearing element in contact with said housing, a drive pulley for said spindle, and a work engaging chuck.

PAUL H. WALTHER.

REFERENCES CITED The following references are of record in the ie of this patent:

Number Number 6 UNITED STATES PATENTS Name Date Cogsdill Dec. 2, 1919 Belden et al. May 18, 1926 Pichler May 19, 1931 Einstein Mar, 15, 1932 Cogsdill Nov. 23, 1937 Polson Feb. 29, 1944 FOREIGN PATENTS Country Date Great Britain Nov. 25, 1911 Great Britain Jan. 5, 1933 

